This paper will compare and discuss the technical performance of Ricoh G6 and Ricoh G5 nozzles from the aspects of color block, small ink drop, ink supply, nozzle heat dissipation, supporting ink, mechanical accuracy, ignition frequency and compatibility.

Color block effect:

Ricoh gen6 nozzle is named mh5320 (hereinafter referred to as G6). The ink droplets changed from 7pl of G5 to 5pl. The smaller ink droplets reflect the finer transition pattern and significantly improve the details of the pattern. When the basic ink drops become smaller, the large ink drops will also become smaller (from the original 21pl to 15pl), which will bring new problems to the printing of color blocks. Under the same pass conditions, compared with G5 nozzle, its coverage depth and uniformity will be slightly inferior. In practical application, it is found that some devices are not linearly effective for the non-uniformity of color blocks, so it is not very effective to solve the problem of large color block uniformity only through multi pass.

Small ink drop effect:

Compared with large ink droplets, the flight speed loss rate of small ink droplets in the air will increase. The positioning effect of small ink droplets of G5 nozzle is better than that of G6 nozzle. From the three-dimensional feeling in the figure, G5 will be better than G6. Therefore, if you want to obtain a good fine pattern after using G6 nozzle, the distance between the nozzle and the medium should be smaller. After using small ink drops, the air flow around the nozzle will increase the influence of ink drop position. Due to the small amount of ink droplets, G6 nozzle is more prone to the problem of uneven printing than G5 nozzle when printing color blocks. Therefore, it is necessary to improve and optimize the mechanical accuracy and control accuracy in order to match with the nozzle.

Ink supply effect:

For G5, when working at the maximum ignition frequency, the maximum amount of ink required per minute is about 33ml, while G6 will increase to 57ml. Therefore, it is necessary to calculate and verify whether the original ink supply system can meet this flow requirement and whether the pressure loss is still within a reasonable range. Otherwise, when the ignition frequency increases, it is easy to break the ink due to improper coordination of the ink supply system.

Nozzle heat dissipation:

When the ignition frequency of the tablet increases, the heating of the nozzle itself will be more obvious. The increase of the temperature in the nozzle will affect the normal printing quality. At the same time, the heat dissipation around the nozzle should be considered.

Ink matching:

The ignition frequency of G6 nozzle has been greatly improved. It should be noted whether its shear rate at high frequency still has the characteristics of Newtonian fluid. At present, most ink factories in the market only pay attention to the static viscosity and surface tension of UV ink, but under dynamic and high-frequency conditions, there is not much research and testing on whether these basic physical and chemical indexes of ink have changed, resulting in the maturity of ink far behind G5 nozzle.

Mechanical accuracy:

In order to realize the ignition frequency of G6 nozzle 50K, if the moving direction accuracy of the vehicle is 600dpi, the moving speed of the vehicle will reach 2.1m/s. When moving at such a high speed, the requirements for machinery will be higher.

When the pattern quality meets the general requirements, the ratio between the movement of the car and the falling of the ink droplets should be at least 1:4, while the falling speed of the ink droplets of the actual G6 nozzle is usually about 6-7m / s 1mm away from the nozzle. To meet this requirement, only the horizontal moving speed with 720dpi accuracy can be selected for printing. If 600dpi is selected, the ratio of horizontal and vertical speed is less than 1:4 At this point, the print quality will decline a lot.

Of course, when the customer's requirements are not high, you can still choose. At the same time, for vehicles with high moving speed, the acceleration area should not be too large. At this time, only the acceleration can be increased. When the acceleration is greater than 1G, it is challenging for the stability of the ink supply system. Therefore, it is necessary to improve the speed of the car rather than make the pressure fluctuation in the ink supply road too large. The ink supply system should add a pressure fluctuation absorption device to reduce the excessive sudden change of pressure on the ink channel and further improve the accuracy and anti wave ability of the negative pressure system.

Ignition frequency selection:

If you want the G6 nozzle to work stably and efficiently, you must find the ignition frequency point suitable for it. After repeated tests, the current ignition frequency point of about 35K is its stable printing frequency point. However, if you want to increase the ignition frequency, the ink drop speed will fluctuate. You need to adjust and optimize the ink supply system in order to realize mechanization.

Ink compatibility:

Compared with G5 nozzle, the compatibility of G6 nozzle is greatly improved, which can meet the needs of users in a wider range of industries.